Sound-absorbent material



Sept. 26, 1933.

H. G. SCHULSTADT SOUND ABSORBENT MATERIAL Filed NOV. 24, 1930 IN V EN TOR.

Patented Sept. 26, 1933 SOUND-ABSORBENT 'MATERIAL Hugo G. Schulstadt, Maplewood, N. 3., assignor to Herbert H. Schulstadt, Maplewood, N. J.

Application November 24, 1930 Serial No. 497,623

3 (Claims.

This invention relates, generally, to soundabsorbent material; and the invention has reference, more particularly, to a novel construction of material for surfacing the walls, ceilings or other exposed areas: of auditoriums, theaters,

rooms and other chambers.

This invention has for its principal object to provide a novel construction of sound-absorbent material, in sheet or panel form, which may be conveniently and economically applied to exposed interior surfaces of auditoriums, theaters, halls .or any other rooms or chambers, to prevent reflection of sound waves from such surfaces, thus eliminating confusing reverberation of sound in such places, and thereby greatly improving the acoustics thereof.

This invention has for a further object to provide a novel construction of sound absorbent material which is strong and durablefeasily and economically produced, and easy to apply in use, while at the same time providing a, material having an uninterrupted exposed surface which is of sightly appearance and which may be pleasingly decorated by dyes, when color effects or designs are desired.

Other objects of this invention, not at this time more particularly enumerated, will be understood from the following detailed description of the same.

An illustrative embodiment of this invention is shown in the accompanying drawing, in which:-

Figure 1 is a perspective view of a soundabsorbent surfacing panel or sheet made according to the principles of this invention, parts being broken away to show the internal construction thereof. Figure 2 is a fragmentary face view of the same, drawn on an enlarged scale, and with the facing material partly lifted away to show underlying structure; and Figure 3 is in part an edge elevation and in part sectional view of a portion of the novel sound absorbent material of this invention.

Similar characters of reference are employed in the above-described views, to indicate corresponding parts.

Referring to said drawing, the novel sound absorbent material of this invention comprises a back or foundation sheet 5. This back or foundation sheet is preferably made of asbestos board; such material being chosen for its fire-proof character. It will be understood, however, that the back or foundation sheet 5 may be made of any other suitable material, such as card-board. fiber board, sheet metal, or in fact any material calculated to provide a comparatively stiff sheet. Said back or foundation sheet 5 need not be of considerable thickness, although as to this it is optional with the manufacturer to select such thickness of material as may seem best adapted 0 for a given use.

The reference character 6 indicates bodies or blocks of porous or interstitial material, preferably composed of felted fibers, such e. g, as wool or hair felt or similar material. The felt blocks 6 are preferably provided of selected geometrical form, and are arranged upon the surface of said back or foundation sheet in spaced apart relation, preferably in such mutual relation that eachsuch block is equally spaced at all 7 sides from its adjacent neighbors. Said felt blocks 6 are of substantial thickness, according to the total thickness of finished panel or sheet it is desired to produce; ordinarily the blocks may range from one-half inch to one inch in thickness. Said felt blocks 6 are preferably secured to the back or foundation sheet 5 by any desired form of adhesive 7 (see Figure 2) such as glue, asphaltum or the like. Other methods and means of securing the felt blocks to the back or foundaso tion sheet may be adopted if desired.

The reference character 8 indicates a reticulate metallic cap, made of -metal screening, which is telescopically engaged over the outerend of each felt block 6 so as to cover the face thereof; the peripheral flange part 8' of each cap telescopically fitting over the end of the felt block to which it is applied. 1

In fabricating the panel or sheet of sound absorbent material, said back or foundation sheet 5 with the attached felt blocks 6 having applied thereto the reticulate metallic cups 8, is placed in a casting frame, which surrounds the bottom and sides of said back or foundation sheet 5. A facing sheet 9 of suitable textile fabric, such, e. g., as canton flannel, or of felted fibrous material, or of any other material which is not substantially sound reflective, is suitably attached to a removable cover-plate of the casting frame, so as to smoothly cover the inner face of the latter. The cover-plate is then assembled with the casting frame, so that the textile fabric facing sheet 9 lies across and in contact with the outer capped ends of the felt blocks 6. When the materials are thus assembled in the casting '12; frame, liquid plastic material, such as plaster of paris or equivalent moldable plastic which dries into a hard rigid mass, is poured into the open end of the casting frame. The plastic material will flow down between the back or foundation sheet 5 and textile facing sheet 9, and around through the spaces between the capped felt blocks 6, filling the latter spaces and bonding at all points to and with the back or foundation sheet 5, textile facing sheet 9 and sides of the capped felt blocks 6 with which it contacts.

The plastic material, thus cast, when dried forms a hard, rigid mass or body 10 between the back or foundation sheet and the textile facing sheet in which each felt block 6 is individually imbedded. The plastic material will interlock with the flange parts 8' of the reticulate metal caps 8 thus also firmly securing the same against displacement from the felt blocks 6 to which they are applied.

After the plastic material has hardened, textile facing sheet 9 is released from the coverplate of the casting frame, and the latter is opened, whereupon the resultant panel or sheet of sound absorbent material is removed, so that the edges of the facingsheet 9 may be trimmed off, thus finishing the panel or sheet so that the same is ready for use.

The panels or sheets of sound absorbent material thus provided may be secured in any suitable manner, either directly to wall studding or to the wall surfaces of a room to be provided therewith. The panels or sheets may be nailed or fastened in place by screws; furthermore, the panels or sheets may be sawn through if necessary in fitting the same when installing in place.

When installed to provide an exposed facing on the walls of a room or other place, the textile facing sheet 9 is outwardly presented, and affords a smooth pleasing surface, susceptible to decoration by colored dyes, if desired.

Owing to the fact that the textile facing sheet 9 is necessarily interstitial, sound waves flowing to the wall panels or sheets will pass through said facing sheet 9 and into the felt blocks 6, being thus readily absorbed by the latter. As a result of this functioning, the sound waves are not reflected from the panels or sheets forming the exposed wall surfaces, and consequently annoying and confusing reverberation or echoing of sounds transmitted within the room or chamber having wall surfaces of the sound absorbent material of this invention is substantially eliminated.

It will thus be obvious that the novel sound absorbent material of this invention is ideal for treating, the walls of auditoriums, halls, theaters or other rooms-or chambers, wherein the clear and unconfused transmission of sound to all parts thereof is desired, and consequently instrumental or vocal music, the speaking voice and sound of like origin may be clearly transmitted and received.

The provision of the reticulate caps 8 intermediate the ends of the felt blocks 6 and the textile facing sheet 9, reenforces and supports the latter against accidental puncturing or similar injury, and yet does not interfere with the sound absorbing function of said felt blocks 6.

I am aware that many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made Without departing from the scope thereof, hence it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

I claim:-

1. A sound absorbent panel, comprising a body of hardened plastic substance, and a multiplicity of felt blocks imbedded in said body so as to be substantially flush with one face of the latter, said blocks being more or less uniformly spaced apart one from another, and a layer of facing material superimposed upon said body over th exterior faces of said blocks.

2. A sound absorbent panel, comprising a body of hardened plastic substance, a multiplicity of felt blocks imbedded in said body so as to be substantially flush with one face of the latter, said blocks being more or less uniformly spaced apart one from another, and a facing of textile fabric on said body to cover the outer faces of said felt blocks.

3. A sound absorbent panel, comprising a body of hardened plastic substance, a multiplicity of felt blocks imbedded in said body so as to be exposed at one face of the latter, said blocks being more or less uniformly spacedapart one from another, a facing of textile fabric on said body to cover the exposed faces of said felt blocks, and reticulate metallic material interposed between said faces of the felt blocks and said textile fabric facing.

4. A sound absorbent panel, comprising a back sheet, a relatively thin pervious facing sheet, interstitial blocks of fibrous material extending between said back sheet and said facing sheet, said blocks being spaced apart one from another, and hardened plastic material surrounding said blocks between said back sheet and facing sheet, said back sheet, facing sheet and blocks being bonded together by said plastic material.

5. A sound absorbent panel, comprising a back 115 sheet, a facing sheet, interstitial blocks of fibrous material extending between said back sheet and said facing sheet, said blocks being spaced apart one from another, and hardened plastic material surrounding said blocks between said back sheet and facing sheet, said back sheet, facing sheet and blocks being bonded together by said plastic material, and reticulate metallic material interposed between said blocks and said facing sheet.

6. A sound absorbent panel, comprising an as- 125 bestos back sheet, a facing sheet of textile fabric, a multiplicity of spaced apart blocks of felt extending between said back! sheet and said facing sheet, and hardened plastic material surrounding said blocks between said back sheet and 130 facing sheet, said back sheet, facing sheet and blocks being bonded together by said plastic material.

7. A sound absorbent panel, comprising an asr bestos back sheet, a facing sheet of textile fabric, a multiplicity of spaced apart blocks of felt extending between said back sheet and said facing sheet, and hardened plastic material surrounding said blocks between said back sheet and facing 4 sheet, said back sheet, facing sheet and blocks ho being bonded together by said plastic material, and reticulate metallic caps on the ends of said felt blocks which adjoin said facing sheet.

HUGO G. SCHULSTADT. 

